(voi'släv kôshtō'nētsä), 1944–, Serbian politician, president of Yugoslavia (2000–3) and prime minister of Serbia (2004–8) b. Belgrade. A constitutional lawyer and liberal anticommunist, he lectured at his Belgrade Univ., but was fired (1974) for his criticism of Tito. A free-speech advocate in the 1980s, he co-founded (1989) Yugoslavia's Democratic party and later founded (1992) and led the breakaway Democratic party of Serbia (DSS). A member of the Yugoslavian parliament (1990–97) during the years of Yugoslavia's breakup and ethnic warfare, he supported a primary role for Serbia within Yugoslavia while opposing the policies of Slobodan Milošević. In 2000, a 18-party opposition coalition picked Koštunica as its presidential candidate, and he defeated Milošević, becoming president of Yugoslavia.
As president, Koštunica rejected the idea of trying Milošević (or others involved in the atrocities of the 1990s) for war crimes. He also tried but failed to preserve the union between Serbia and Montenegro, the last remaining Yugoslavian republics, and it was ultimately dissolved in 2006. In 2003 he was elected to the Serbian parliament and became (2004) prime minister of Serbia, heading a center-right coalition, and remained in that post at the head of a revamped coalition after the 2007 elections.
While continuing to oppose the Hague tribunal process for prosecuting Yugoslavian war crimes, Koštunica moved to fight corruption and unemployment, worked toward Serbian membership in the European Union, and emphasized the preservation of Serb rights in Bosnia and in Kosovo, where he strongly opposed any move that would lead to the region's independence. After Kosovo declared independence in Feb., 2008, he resigned and forced the calling of new elections, objecting to his coalition partners' continuing support for joining the EU after Kosovo had been recognized by many EU members. He remained leader of the DSS until 2014, when he resigned after the party failed to win any seats in parliament; he later quit the DSS over disagreements with the new leadership.